Nurse′s A‐Phase: Synthesis and Characterization in the Binary System Ca2SiO4–Ca3(PO4)2

In the present study, a new single phase Si–Ca–P‐based ceramic was obtained by conventional sintering of compacted mixtures of calcium hydrogen phosphate anhydrous, calcium carbonate, and silicon oxide. The synthesis conditions were the followings: heated up to 1550°C for a total period of time of 72 h (3 d), with quenching in liquid nitrogen, milling, pressing, and reheating every 24 h. Second, heating at 1300°C/3 h and subsequent annealed at 1200°C/24 h. Mineralogical and microstructural characterization of the obtained Si–Ca–P‐based material was determined by Differential Thermal Analysis, X‐ray diffraction, Scanning Electron Microscopy with attached wavelength dispersive spectroscopy, Micro‐Raman and Fourier Transform Infrared Spectrometer. The results showed a single Si–Ca–P phase material with a Ca₂SiO₄/Ca₃(PO₄)₂ molar ratio equal to 2:1. The parameters of the Weibull distribution of strength, determined by diametrical compression of disks, were: modulus, m = 13, and characteristic strength σ₀ = 0.60 MPa.